1. Technical Field
The present disclosure relates to a display device that can detect an external proximity object, specifically, a display device with a touch detection function that can detect an external proximity object based on a change in capacitance, a method for driving the display device with a touch detection function, and an electronic apparatus.
2. Description of the Related Art
In recent years, a touch detection device that can detect an external proximity object, what is called a touch panel, has been attracting attention. The touch panel is used for a display device with a touch detection function that is mounted on or integrated with a display device such as a liquid crystal display device. The display device with a touch detection function displays various button images and the like on the display device, so that information can be input using the touch panel instead of an ordinary mechanical buttons. The display device with a touch detection function having such a touch panel does not need an input device such as a keyboard, a mouse, and a keypad, so that the use thereof tends to expand to a personal digital assistant such as a cellular phone, in addition to a computer.
Examples of a type of the touch detection device include, but are not limited to, an optical type, a resistance type, an electrostatic capacitance type, and the like. When the electrostatic capacitance type touch detection device is used for a portable terminal apparatus and the like, devices having a relatively simple structure and low power consumption can be provided. For example, an electrostatic capacitance type touch panels are disclosed in Japanese Patent Application Laid-open Publication No. 2011-233018 (JP-A-2011-233018) and Japanese Patent Application Laid-open Publication No. 2012-047807 (JP-A-2012-047807).
As a technique for reducing a thickness of a display device with a touch detection function, known is that a drive electrode for display also functions as a drive electrode for touch detection, for example. In such a case, a display period and a touch detection period are separately provided because in the display period in which a scanning signal is applied from a gate driver, a display driving signal and a touch driving signal cannot be applied to the drive electrode simultaneously.
Although not limited to the above configuration, when the thickness of the display device with a touch detection function is reduced, a distance between a signal line and a touch detection electrode is reduced. Accordingly, when the display and the touch detection are performed at the same time in the same region, the display of the display device may affect the touch detection of the touch detection device in some cases.
However, to achieve a large screen size and high definition in the display device, time required for the display by the display device is increased. Therefore, in a case in which the screen size or the definition of the display device is increased, the display period of the display device is relatively increased and the touch detection period of the touch detection device cannot be secured enough, so that the display device with a touch detection function cannot sufficiently perform the touch detection and may be weak against a noise and the like. The display devices with a touch detection function disclosed in JP-A-2011-233018 and JP-A-2012-047807 do not take the fact into account that the display period of the display device is relatively increased and the touch detection period of the touch detection device cannot be secured enough, so that the touch detection cannot be sufficiently performed and can be weak against noise and the like.
For the foregoing reasons, there is a need for a display device with a touch detection function, a method for driving the display device with a touch detection function, and an electronic apparatus that can secure the touch detection period sufficiently while suppressing the influence of the display by the display device on the touch detection.